[Server:server-three] 11:31:44,782 WARNING [org.jgroups.protocols.UDP] (pool-12-thread-1) send buffer of socket java.net.DatagramSocket@7139acf was set to 640KB, but the OS only allocated 131.07KB. This might lead to performance problems. Please set your max send buffer in the OS correctly (e.g. net.core.wmem_max on Linux)

[Server:server-three] 11:31:44,784 WARNING [org.jgroups.protocols.UDP] (pool-12-thread-1) receive buffer of socket java.net.DatagramSocket@7139acf was set to 20MB, but the OS only allocated 131.07KB. This might lead to performance problems. Please set your max receive buffer in the OS correctly (e.g. net.core.rmem_max on Linux)

[Server:server-three] 11:31:44,785 WARNING [org.jgroups.protocols.UDP] (pool-12-thread-1) send buffer of socket java.net.MulticastSocket@747fee41 was set to 640KB, but the OS only allocated 131.07KB. This might lead to performance problems. Please set your max send buffer in the OS correctly (e.g. net.core.wmem_max on Linux)

[Server:server-three] 11:31:44,786 WARNING [org.jgroups.protocols.UDP] (pool-12-thread-1) receive buffer of socket java.net.MulticastSocket@747fee41 was set to 25MB, but the OS only allocated 131.07KB. This might lead to performance problems. Please set your max receive buffer in the OS correctly (e.g. net.core.rmem_max on Linux)

[Server:server-three] 11:31:51,979 WARNING [org.jgroups.protocols.UDP] (pool-13-thread-1) send buffer of socket java.net.DatagramSocket@3c23af64 was set to 640KB, but the OS only allocated 131.07KB. This might lead to performance problems. Please set your max send buffer in the OS correctly (e.g. net.core.wmem_max on Linux)

[Server:server-three] 11:31:51,980 WARNING [org.jgroups.protocols.UDP] (pool-13-thread-1) receive buffer of socket java.net.DatagramSocket@3c23af64 was set to 20MB, but the OS only allocated 131.07KB. This might lead to performance problems. Please set your max receive buffer in the OS correctly (e.g. net.core.rmem_max on Linux)

[Server:server-three] 11:31:51,982 WARNING [org.jgroups.protocols.UDP] (pool-13-thread-1) send buffer of socket java.net.MulticastSocket@18d5e26b was set to 640KB, but the OS only allocated 131.07KB. This might lead to performance problems. Please set your max send buffer in the OS correctly (e.g. net.core.wmem_max on Linux)

[Server:server-three] 11:31:51,983 WARNING [org.jgroups.protocols.UDP] (pool-13-thread-1) receive buffer of socket java.net.MulticastSocket@18d5e26b was set to 25MB, but the OS only allocated 131.07KB. This might lead to performance problems. Please set your max receive buffer in the OS correctly (e.g. net.core.rmem_max on Linux)

How was this resolved, finally? I follow the guide to configure cluster on Windows 2008 R2, and when I start up the slave, it always can't connect to remote domain controller, but I can telnet to the manager's port:9999